Microcapsules are used in many fields such as recording materials such as pressure-sensitive recording paper and heat-sensitive recording paper, agrochemicals, medicines, perfumes, liquid crystals, and adhesives. As the method of producing microcapsules, many methods have been proposed, and known typical methods of microcapsulation include a coacervation method, an interfacial polymerization method, an in-situ polymerization method, etc. (see Kondo and Koishi: Microcapsule and Its Process, Properties, and Application, published by Sankyo Shuppan).
As information related devices have been developed in recent years, data on various kinds of information are increasing, and information is outputted in various forms. The information is outputted generally in displays using cathode-ray tubes or liquid crystals. In these displays, portability and low-energy consumption are required, and novel displays are extensively developed. As novel displays, electrophoretic displays have been proposed (see Japanese Patent Application Laid-open No. H1-86116 and U.S. Pat. Nos. 6,241,921 and 6,262,706).
The electrophoretic display is constituted by encapsulating, into microcapsules, a dispersion system having electrophoretic particles dispersed in a dispersing medium colored in a tint different from that of the particles, and arranging the microcapsules between electrodes. The electrophoretic display is a reflective display which like a liquid crystal display, does not require a backlight. Accordingly, the electrophoretic display has advantages such as reduction in the burden on users' eyes, viewability at different angles, and re-writability in a relatively short response time. Further, the electrophoretic display has memorizability by which electrophoretic particles moving to the electrodes upon application of voltage across the electrodes can be maintained in the same state for a long time even after the voltage is removed. Accordingly, the electrophoretic display is expected to have excellent performance by which no electric power is required for the time when certain display is maintained.